1. Field of the Invention
The present invention relates to an electronic apparatus including a remote control receiving system, an AC adapter system and so forth.
2. Description of the Related Art
The structure of a conventional remote control receiving system is shown in FIG. 4. The conventional remote control receiving system includes a power source dedicated to a remote controller (hereafter called as xe2x80x9cremote control power sourcexe2x80x9d) 200 independently of a system power source 100 for driving a load of a system (for example, a television receiver).
The remote control power source 200 is comprised of an isolation transformer 201, a rectifying unit 202 and a stabilized power source circuit unit 203. A DC voltage of, for example 12 V, obtained by the rectification of the rectifying unit 202 is supplied to a relay driving circuit unit 205 for driving a relay in an AC switch unit 204 as its operation voltage. Moreover, a DC voltage of, for example 5 V, obtained by the stabilization of the stabilized power source circuit unit 203 is supplied to a remote control light receiving unit 206, a microcomputer unit 207 and a standby display unit 208 as respective operation voltages.
However, not only the consumption electric power of the remote control light receiving unit 206, the microcomputer unit 207 and so forth, but also the reactive loss of the isolation transformer 201 are large in the conventional remote control receiving system structured as above. Consequently, the consumption electric power of the system is large, and the improvement in saving electric power at the time of stand-by for being remotely controlled is desired.
The present invention was made in consideration of the aforesaid problem, and aims to provide an electronic apparatus capable of saving electric power at the time of stand-by.
According to an aspect of the present invention, there is provided an electronic apparatus in a structure of comprising a regulator for driving a load connected to an output terminal of the regulator by using an AC power source as an energy source, a charger connected to the output terminal of the regulator, a charging switch connected between the load and the charger, and switch controlling means for monitoring a charged voltage in the charger to turn on the charging switch when the charged voltage reaches a prescribed voltage and turn off the charging switch when the charged voltage becomes less than the prescribed voltage.
When the charged voltage in the charger is less than the prescribed voltage in the electronic apparatus having the aforesaid structure, the switch controlling means turns off the charging switch. At this time, an operation voltage is supplied to the load from the regulator together with charging of the charger by the voltage of the regulator. And then, when the charged voltage in the charger reaches the prescribed voltage, the switch controlling means turns on the charging switch. Hereby, because the voltage in the charger is supplied to the load through the charging switch, the electric power consumption to the load on the side of the AC power source is suppressed.